Re: pata_amd dropping to PIO on resume

[Jeff Garzik <jeff@garzik.org>]

Robert Hancock wrote:
> Tobias Diedrich wrote:
>> Possibly a known issue:
>>
>> After resume pata_amd drops from UDMA/33 to PIO on my system.
>> Reloading the module puts both attached optical drives (master and
>> slave) back to UDMA/33.
>>
>> AFAICS "simplex DMA is claimed by other device, disabling DMA" seems
>> to be causing it to drop to PIO (but only after a suspend/resume
>> cycle, not on boot or module load).
>>
>> Burning a DVD with 6x speed using PIO makes heavy use of burnproof
>> and makes the whole system quite sluggish. :)
> 
> Yes, the fact that it's going into simplex mode is the problem, it 
> wasn't in simplex to start with. It looks like pata_amd does an 
> ata_pci_clear_simplex only for certain chip models, maybe this model 
> needs it as well?
> 

Deleting the ata_pci_clear_simplex() call, then adding 
ATA_FLAG_IGN_SIMPLEX to the ata_port_info info[] array, is also worth 
trying.

	Jeff